Steering apparatus



Dml 26, 1939.

B. CHNCE v STEERING APPARATUS 11 Sheets-Sheet 1 Filed oct. a, 19:57

D@n 26,1939. B. CHANCE 2,185,074 v SKTEERING APPARATUS Filed Oct. 8,- -193'? 1l Sheets-Sheet 2 26, 1939. B. CHANCE Y2,185,074

NG APPARATUS Oct. 8, 1937 llySheetS-Sheet 3 11 sheets-sheet 5 Dec. 26, 1939. B. CHANCE Y STEERING APPARATUS 11 Sheets-Sheet 6 Filed Oct. 8,- 1937 wphqys,

Dec. 26, 1939. y B CHANCE STEERING APPARATUS Filed oct. a, '1937- llsheets-sheet '7 W WWW W W W w @Wemag- 26, 1939. BCHANC .2,185,074 I v STEERING APPARATUS Filed oet. e, 19:57 11 sheets-sheet s Dec. 26, 1939.

B. CHANCE STEERING APPARATUS Filed oct. e, 1937 11 sheets-sheet 9 B. CHANCE STEERING APPARATUS Dec. 26, 1939.

Filed Oct. 8, 1937 ll Sheets-Sheet l0 grim Zaza/J6 Dec. 26, 1939. B. CHANCE STEERING APPARATUS 1l Sheets-Sheet 11 Filed Oct. 8, 1937 Patented Dec. 26, 1939 UNITE-D .STTES PATENT `oi-"l-"icls 21 Claims.

This invention relates to a novel automatic steering system forxdirigible bodies or craft such as vessels, aeroplanes and thel like.

One object of the. invention is. to provide al I system of this class which comprises essentially a controlling unit or devicer adapted to be disposed inthe tranquil zone of a.craft, or in other words, 'at a position of least instability, and a controlled unit or device adapted to be disposed m on the craft .at any desired position remote from the controlling unit. The controlling unit responds to deviations of the craft from its course and controls `the controlled unit accordingly,

lcausing the latter to actuate the steering mechau nism of the craft to bring the craft back on its course. Follow-back action is effected at the controlling unit by suitable means which preferablyv takes the form of a flexible rotary cable' extending between the two units, this being the only lo mechanical connection between them. By vir- A tue of the provision of the two units and their adaptability forl disposition on the craft as above mentioned, the control action is caused to be in accurate response to deviations of the-craft from l its course and is unaffected by extraneous influence, such as rolling or other such motionof the craft. Moreover, the system enables positioning of the controlled unit at any desired position on the craft irrespective of the position of the conan trolling unit.

In addition to the ability to place the controlling unit in'the tranquil zone of the ship, the invention enables the placing of that unit at th point in the ship where the earths magnetic iiux 35 is least warped or damped by the ships magnetism and is. therefore, at a maximum. The optimum position for locating the controlling device, therefore, must take into consideration both the tranquil zone and this position of maximum 404 undistorted magnetic effec Another object of the invention is to provide a novel system `of this character wherein the controlled unit embodies a vcourse indicator. Accordingly, the controlled unit may' be disposed 45 on the craft at any desired position where it is desired to give a lcourse indication. For example, this unit may be `disposed at the position o manual control of the craft so that the pilot or craft during operation of the automatic steering system.

A further object of the invention is to provide means for changing the course of the craft manually at will using the follow-back connechelmsman may be apprised of the course of the I v at will to meet varying weather or climatic conditions and the sensitivity of the system may be varied. l l

Still another object of the invention is to provide novel means for preventing control action' 15; when the ship rolls or moves in any manner other than angularly in azimuth with respect to its course. A Other objects and features of the invention will appear hereinafter. 20.

In the accompanying drawings: j A

Fig. 1 is a diagrammatic illustration of the manner in which the two units may be positioned on a craft such as a vessel;

Fig. 2 is a sectional elevational vview of one 25s form of the controlling unit; Y

Fig. 3 is a plan view of the same unit with the cover removed;

Fig. 4 is a sectional detail view taken along line 4-4 of Fig. 3;

Fig. 5 is an elevational view of one form of the controlled unit; s

Fig. 6 is an elevational view of the same unit looking at the unit from the left-hand side as viewed in Fig. 5, a portion of the casing being 35 broken away for illustration of certain details;

Fig. 7 is a sectional plan view taken along line 1--1 of Fig., 6; Y

Fig. 8 is a-perspective view of a frictional drag device employed in the controlled unit; 40

Fig. 9 is a fragmentary sectional elevation oi the upper part of the controlled unit taken along line 9-9 of Fig. 7;

Fig. 10 is a sectional detail view of one of the differential mechanisms employed in the controlled unit; l

Fig. 11 is a similar view of another differential drive mechanism embodying the follow-back ad.- justments; .Y

Fig. 1 2 is an exploded view showing in perspec- 50 tive certain parts of the adjustable lost-motion mechanism employed in the drive of Fig. 11;

Fig. 13 is a phantom elevational view of the controlled unit illustrating the flexible drive connectionsv thereof; 55

Hg. 14 is a diagrammatic illustration of a simple electrical circuit which may be employed Fig. 15 is an elevational view of an alternative form of the controlled unit;

Fig. 16 is a fragmentary sectional view taken along line lt--I of Fig. 15;

Fig. 17 is'a phantom view illustrating further the speed change mechanism of the controlled unit:

Fig. 13 is a plan-view'of an alternative form of the controlling unit;

Fig. 19 is a sectional elevational view of the same; and

Fig. 20 is a diagrammatic illustration of the electrical circuit of the modified device.

Referring to Fig. l, there is illustrated diagrammatically a vessel i which is representative of any dirigible body or craft on which the invention may be employed, it'being understood that the invention is adapted foruse on other types of craft such as aeroplanes and the like. The diagrammatic illustration of Fig. 1 represents the portion of a. vessel above the water line and shows successive decks of the vessel. The controlling unit or' device 2, provided in accordance with the invention, is disposed on one ofthe decks of the vessel. The controlling unit or device\2, provided in accordance with the invention, is disposed on one of the decks as shown in the tranquil zone oi' the vessel, or in/other words, at a position of least instabilit-#while the controlled unit or device 3 is disposed at a desired position remote from the controlling unit il. In the specific illustration1 the controlledunit 2 is mounted on the bridge of the vessel as it is likely that such positioning of the controlled unit will generally be desirable, in order that Vthe helmsman may be apprised of the course of the 'craft and may vary the course manually and may adjust the follow-back action, as described hereinafter. The controlled unit 3 is mechanically connected to the usual steering mechanism d of the craft. As' illustrated, this mechanical conxiection comprises a flexible chain 5 extending between sprockets on the unit 3 and the steermanner and the control panel 'I is merely for convenience of mounting the electrical devices v%1'!1l loyed and does not constitute an essential element ofthe invention. Follow-back action is effected by means of a mechanical connection 25 between the units 2 and 3, as will be described in detail later.

Referring now to Figs. 2 to 4, there is illustrated in' detail one form of the controlling unit or device 2. This unit comprises a support or housing 8 which is adapted to be rigidly mounted upon the craft at a predetermined position in the tranquil zone of the craft, as above indicated.

A removable cover 9 serves, together with the support or housing, to house the elements Vof the device. Within the housing thus provided, there is mounted a gimbal ringlll which is attachedto the support 8 by means of the opposed pin bearings or journals I I (see Figs. 3 and 4).- As shown more clearly'in Fig. 4, the gimbal ring; I3

are attached to the support l. As shown more clearly in Fig. 2, the gimbal ring I0 carries a suspended yoke` I4 which is supported by means of diametrically opposed 5 pin bearings or journals l5. The yokel Il is Weighted as shown at I6 to maintain it in position and to resist movement due to rolling or other such motion of the craft. A cup-shaped member i7 is rotatably supported by the yoke 10 I4, and to this end the member Il is provided -with a centrally disposed downwardly extend- V@ing stud or spindle I8 which is rotatably supported on the yoke I4 by means of the bearing structure I9. A slip-ring structure 20 is ar- 15 ranged cooperatively with the spindle i8 and serves to make electrical connection to the electrical elements carried byl member Il, as mentioned hereinafter. The side wall of the cupis thus supported by brackets 4I3 which, in turn,

shaped member Il is supported by the rollers 2i 20 pose of this shaft Will be explained more fully later.

The cupshaped member l1 lcarries a plurality of light-sensitive devices, such as photoelectric cells, and preferably there are provided three such devices or cell units, as shown in Fig. 3, comprising side units 26 and 21 and a central unit 28. Each of the cell units preferably oomprises a casing 29 and a photoelectric cell 3ft therein, as shown in Fig. 2. In cooperative relation with the photocell units, there-are pro- 40.

vided a pair of triangular prisms 3l and 32 associated respectively with the cell units 26 and 2l (see Fig. 3). The cell unit 26 and its associated prism 3l are mounted upon a support 3.3 which is adjustably carried upon the upper rim or flange of the cup-shaped member I1, while the cell unit 27 Aand its associated prism 32 are likevw'ise mounted upon an adjustable support 36. Thus, each of the side cell units with its `associated prism may be adjusted relatively to the I central unit 2li-to vary the response of the lightsensitive mechanism, as described more fully hereinafter.

A spider 35 is also carried by the cup-shaped member I1 and serves to support the bowl of a 55 .magnetic compass. 35a within the member il.

A bracket 35h, also carried by the cup-shaped member I1, serves to support a lamp housing 35o in vsuch manner that a lamp within the lamp housing projects ra. light beam downward substantially in axial alignment with the axis of the compass card. A reflecting device or mirror 35d is carried by the compass card and is mounted in substantial alignment with the axis thereof, and this reflecting device is adapted to reect the light beam toward the light-sensitive mechanism as indicated in Fig. 2. This arrangement provides a reflected beam of light which is fixed in space and which remains fixed regardless of change in direction of "travel vof the craft. I nother` words, since the compass card remains fixed in position and .the reflector 35d is carried at the axis of the compass card and since the projected light beam is substantiallyin alignment with theaxis of the compass card, ro- 75 tation of the projected beam about its axis will not vary the position o`f the beam relative to the reflector 35d and the reflected beam will, therefore, remain in fixed position.

When the/craft is on its course, the reilected beam is directed into the space between the prisms 3| and 32, as may be seen in Fig. 3, and

v the beam impinges upon the central light-sensi- 'tive device 28'. When the craft deviates from its course in one direction or the other, however, the support 8 moves accordingly, carrying with it the lstructure above described including the cup-shaped member |1 and the light-sensitive mechanism. Thus, the light-sensitive cell assembly is moved toward one side or. the other of the fixed reflected beam and, as a result, the

-beam impinges upon one or the other of the prisms 3| and 32 and is reflected by the prism onto the associated light-sensitive device 26 or 21. The side cell unit, which is thus activated in response to deviation ofthe 'craft from its course, `effects control of the controlled unit or .device 3 in a manner `to bring the craft back on 'activation of the devices 26 and 21 by the light In this manner, adjustment of the re,

beam.

. sponse of the controlling yunit may be made to meet varying weather o'r climatic conditions.

The electro-optical device above described is f generally. similar' to that disclosed and claimed in United States Patent No. 2,102,511, granted December 14, 1937, wherein there is provided a reflecting device and a light source mounted in cooperative relation with a compass card as above described, and there is also provided a group of three light-sensitive devices cooperatively arranged with the reflected light beam to function in the manner above dcribed.

Referring now to Figs. to 13, there is illustrated in detail one form of the controlled unit or device 3 which is controlled electrically by the controlling unit or device 2. As illustrated, the controlled unit may comprise a supporting framework 36 or the like adapted to support the driving mechanism and upon which there is mounted a housing 31- carrying. a course'indicator and manual controls, as will be presently described. The upper part of the unit, including the housing 31, may, therefore, be disposed ata desired position Within easy access of the pilot or helmsman of the craft. In'the case of a vessel, for example, the housing 31 may project upward from the'floor of the bridge in the immediate vicinity of the manual steering control mechanism so that the helmsman may vobserve the course indication given by the course indicator and may also actuate the controls hereinafter described.

Referring particularlyto Figs. 5and 6, a reversible motor 38 serves to drive a shaft 39l through a Vspeed-reduction mechanism 40. A sprocket 4I is loosely mounted upon the shaftf39 and is adapted for mechanical connection to the shaft through the clutch 42 which is operable by the hand lever 43. Thus, by actuating the clutch, the sprocket 4| may be engaged or disengaged with respect to shaft 39 at will. The sprocket 4| is connected by a flexible drive, such as' a chain, to the manual steering mechanism if the craft. 1n ng. 1, this driving connection providing a sprocket on the shaft of the handwheel steering mechanism of the craft, and by lconnecting that sprocket with the sprocket 4I by means of a chain, the sprocket 4| may be caused to actuate the steering mechanism of the craft.

A gear 44 mounted upon shaft 39 meshes with gear 44a (see Fig. r13) and serves to drive a limit switch 'within the housing 45, which switch controls the limit of. rotation 4of the motor 38 in -either direction, as will be described in further detail flater.

At the end of the shaft 39,P there is provided a sprocket 46 connected by a chain 41 to a sprocket 48 carried upon an internally threaded hub 49 (see Fig. 11) mounted upon the threaded "end of al shaft 50. One end of the shaft 50 is journaed in a support 5|, while the other end of this shaft extends into the differential gear mechanism 52 to be described later. Adjacent the 'support 5|, the shaft 50 carries a nut 53 which is secured to the shaft and turns therewithl The nut 53` has an extending lug 54 (see Fig. l12)- which is adapted to cooperate with an extending lug 56 on the adjacent end of the hub 49. On the opposite side of the hub 49 there is provided an internally threaded gear 56 which is likewise carried uponl the threaded portion of the shaft 50 and which has an extending lug 51 adapted to cooperate with the extending lug 58 on the adjacent end of hub 49..

It Will be seen then that the nut 53 is fixed in position axially of the-shaft 50, while the gear Y56 is adjustable axially along the shaft. When the gear 56 ismaintained in a. vcertain adjusted position, itr serves, together with the nut 53, to define the range of possible movement of hub 49 axially of the shaft 50. By virtue of this arrangement, an adjustable lost-motion connection is provided between the ymotor-driven shaft 39 and the shaft 50 for eitherdirection of rotation of the shaft 39. In the position of the parts shown in Fig. l1, the hub 49 is interlocked with the nut 53 and if the shaft 39 were rotated in a certain direction; the shaft 50 would be driven through the interlocking members 53 and 49, but

-is shown at 5, as vabove mentioned. Thus, by

if the shaft 39 were driven in the opposite direcas the'description proceeds.

The shaft also carries a gear 59 and a bevel gear 6B forming a part of the differential gear device 52. The gear 60 is connected to the opposite bevel gear 6| through the gears 62 carried by the differential housing 63, as willbe well understood. 'I'he gear 6| is carried at the end of a shaft 64 whose opposite end is journaled in the support 65. The differential housing 63 is mounted in journal sprockets 66, and to the hub of the housing there is secured a sprocket wheel 61. The shaft 64 carries a sprocket Wheel 68 and a gear 69. As shown in Fig. 5, the gear 69 meshes with a small gear 80 which drives the flexible shaft 25, which shaft, in turn, drives' the worm 24 of the controlling unit 2, as described above in connection with Figs. 2 to 4.

Adjacent the differential gear drive above described, there is provided a second differential gear'drive as shown in Fig. l0. The journal 75 4 a,1ss,ov4

'ipports 88 carry the housing 10 of the differential geardevice 1|. At one side of the differentialgear"mechanism,P there is provided ash'aft 12 carrying at one end the differential bevel gar 13 'and at its other end the sprocket wheel 14. At the other side of the differential gear mechanism, there is provided a shaft 15 carrying at one end the bevel gear 18 and at its other end a gear 11 which meshes with the gear 56. 'I'he bevel gears 13 and 18 mesh with the gears 16a carried 4by the differential housing. The end of shaft 15 is journaled in the support 18. A gear 10 is carried upon the extending hub of the differential housing 10 and meshes with the gear 59.

As may be seen in Figs. 6, 9, and 13, the sprocket wheel .81 is connected by a chain 8| to a sprocket wheel 82-mounted upon a shaft 83 extending 'transversely of the housing 31 near the upper end thereof. The ends of theshaft 83 are rotatably mounted in the'journal supports 88 and 85, respectively. O ne end of the shaft 83' projects through the housing 31, as shown in Fig. 9, and carries the hand wheel 88. A brakelike device 81, shown more clearly in Fig-. 8, is carried by the journal support 88 and serves to impose a drag upon the shaft 83. This brakelike device comprises hinged parts 88 and 88 which are adjustable by means of the adjusting `screw 90 to impose `a desired amount of fricigonal drag upon a drum 83a carried by the shaft A sleeve 9| is rotatably `mounted upon theV shaft 83 and carries at one end a sprocket wheel 82 which is connected to the sprocket wheel 18 by means of a chain 83., The other end of the sleeve 9| projects through the housing 81 and .carries a hub 88 upon which there is mounted a manually-operable pawl 95 having an operating handle 96. 'Ihe pawl 85 is adapted to engage a 1 stationary ratchet 91 carried by the support 05.

At the upper part of the housing 31, there-is provided a courseeindicating card 98 corresponding to the compass card. The card 88 mounted upon a rotatable shaft 08 at the lower end of which there is provided a worm-wheel H00 which is actuatable by a worm |01 (see Fig. 7). The

worm shaft, which is rotatably supported upon shelf ila, carries a sprocket wheel |02 which is connected by chain|03 tothe sprocket wheel 88.

The shelf I 0|a. also supports. the lower part of shaft 99, as may be seen in Fig. 9. A transparent member ma at the upper epd of the housing a1 hereinafter.

' adapted, respectively, to actuate'the pivoted ,ar-

matures |01 and |08. The armatures, in turn, control the energization of motor 38., lThe ce'ntral light-sensitive unit 28 is connected to relay windings |00 and`||0 which also serve to actuate the armatures .|01 and |08, respectively. When the reflected light beam impinges upon the central light-sensitive device, as will Abe the case when the craft is on its course, the windings |08 and ||0 alone are energized and serve to maintain the pivoted armatures in the positions shownv lso that the motor 38 is deenergized. If the craft deviates from its coursel in such direction as to cause the reflected light beam to impinge upon the light-sensitive device 26, the winding |05 is selectively energized and causes the armature |01 to close a circuit for motor 38 as follows: From the supply-conductor IIIv through conductor H2,

armature |01. conductor ||3, the motor 38,l con- '88 and 80a. above mentioned. It will be understood that the limit switch merely serves to define the maximum possible range of actuation of the motor and normally the limit switch contacts will remain closed. By means of the follow-,back action described hereinafter, the light beam is caused to again impinge onlthe central cell unit 28,' thus deenergizing the motor 38.

If the craft deviates from its course in the opposite direction, the reflected light beam will impinge upon the light-sensitive device 21 and will will cause selective energization of the winding B08. As a result, the pivoted armature |08 will be actuated to close a circuit for motor 38 as follows: From supply line lll through conductor H0, armature- |08, conductor |20, the motor 38, conductor 12|, armature |08, conductor |22, the limit switch contacts 23 to the other supply conductor li 1. It will be noted that inlthis instance the motor connections will be reversed with respect to the supply conductors so that the motor will operate in the opposite direction to bring lthe Considering now the operation of the above-y described system as a whole, as long as the craft remains on its course, the central light-sensitive unit 28 will be energized and will maintain the motor38 in deenergized condition, as above described. Should the craft deviate from its course in either direction, however, one or the other of the side light-sensitive units 28 and 21 will be energized and will cause energization of the motor 38 ingthe proper direction. Assuming that the clutch 42 is engaged, the motor 38 will .drive the sprocket 4| which, in turn, will actuate the steering mechanism of the craft as above described in a direction to bring the craft back on its course. At the same time, the shalft 80,

which is driven by the motor 38, will drive the sprocket 48, causing it to engageone or the other of the elements 58 and 56, depending upon the direction of rotation of the sprocket 48. If the direction of rotation is such as to cause the hub 48 to engage the nut 58, the shaft 50 will be directly vdriven and, since the housing of the dif- .ferential gear device 52 is maintained stationary by the brake-like device 81, the shaft `50* will drive the shaft 84 which, in turn, will drive the flexible shaft 25 through the medium of gears 60 land 80. Rotation of the flexible shaft 25 causes the light-sensitive cell assembly to move relative to the light beam until the beam again impinges the course-indicator card 98 through the medium.

upon the central light-'sensitive unit n and thus deenergizes the motor 33.-

In the meantime, the shaft 64 will also drive of the chain drive |03 and the worm |0| and worm-wheel |00. Thus, thecourse indicator is caused to indicate the rudder movement which has been effected by the control action or the new course which the vessel would follow by virtue of the new rudder position were it not for the force which caused the craft todeviate from the desired course. If the craft continues to deviate from its course in the same directlomthe abovedescribed action will be repeated so that successive variations of the position of the crafts rudder will take place until sufficient rudder movementis effected to bring the craft back on the desired course.

Suppose now that the craft deviates from its course'in the opposite direction, causing the sprocket 40 to move in the opposite direction until the hub 49 engages the gear 56. Since the shaft 12 is maintained stationary by the locked condition of 'the ratchet and pawl device 95, 91,

the gear 56 will drive the shaft 50 through gear 11, shaft 15, the rotatable housing 10 'of the differential gear device 1|, gear 19 and gear 59.

- There isthus provided a driving connection from gear 56 to shaft 50 through the differential gear device. 1|, which prevents the gear 56 from rotating relative to shaft 50. Shaft 64 will then be driven by shaft 50 through the differential gear device 52 in the manner above described, thus effecting follow-back action through the medium of the flexible shaft 25 and'also actuating the course indicator.

As above described, -predetermined lost-motion is introduced between the shaft 39 and shaft 50 by virtue of the spaced elements 53 and 56 angl the axially movable sprocket .48 therebetween. This provides a time lag in the operation of the follow-back mechanism and enables a desired amount of rudder actuation, before the follow-back action becomes effective. This time lag may be varied by adjustingv the position of the axially movable gear56. Whenever it is desired to adjust the time lag, the ratchet device 95, 91 is released and the handle 96 is rotated in either direction to a new position and the ratchet device is again locked. The rotation of sleeve 9|, which is thus effected, rotates the shaft 12 through the chain drive 93,. Since the housing `1|) of the differential gear device 1| is maintained stationary by the intermeshed gears 19 and 59, the shaft 12 rotates shaft 15 through the differential gear device 1|, causing gear 11 to rotate gear 56 relative to shaft`50 and causing the gear 56 to move axially along shaft 50 in one direction or the other, depending upon the direction in which the handle 96 is rotated. In this manner, the gear 56 may be moved toward vthe left or right as viewed in Fig. 11, thus varying the vaxial range through which the sprocket 48 may move. It will be noted that the face of gear 56.

is of sufcient width. to permit it to move axially while still bein'g intermeshed with-'gear 11. Thus, the time lag in the follow-back action may be varied at will to meet varying climatic or other conditions affecting the craft. This feature imparts greater flexibility to the system, enabling adjustment of the'system to meet varying conditions.

If it is desired to change the course of the craft at any time, this may be accomplished by causing rotation of the flexible shaft 25 to move direction of the change desired. Rotation Vof the handswheel 86 causes rotation of the shaft 83 against the frictional drag imposed thereon 'i lby the device 81. 'I'he shaft 83, in turn, rotates the housing of the differential gear device 62 through the chain drive 6|. 'I'he shaft 64 is thus driven by the rotating housing 63 and in turn ro- `tates the flexible shaft 25 through the medium of gears 69 and 80; At the same time, the course indicator is actuated through the chain drive |03. Thus, the iiexible shaft.25 is utilized to change .the course of the craft at will, Y in addition to serving as a part of the drive for the follow-back action.

When the clutch 42 is disengaged, the motgr 33 will, of` course, be'ineiective to actuate the steering mechanism of the craft and the automatic steering function of the system is thus inter# Arupted. At such time, however, ythe motor 36 will continue to be actuated in accordance with the deviation of the craft from its course and will serve to actuate the course indicator and also to effect follow-back. action of the light-sensitive devices. In other words, the system will then serve merely as an automatic course indicator.

.In Figs. 15 to 17, there is illustrated a modified form of the controlled unit wherein the lostmotion or time lagdevice above described is replaced by a manually adjustable 4transmission so that the speed of the follow-back mechanism may be controlled to give varying amounts of Aao rudder action for a given deviation of the craft from its course. In other words, instead of employing a time lag or lost-motion device to delay the follow-back action and thus control the amount of rudder action for a givendeviation of the craft from its course, the modified form of the controlled unit illustrated in Figs.

15 to 17 employs an adjustable transmission des vice in the follow-up mechanism to vary the speed of the follow-up action and thus govern the Referring particularly to Fig. 15, the sprocket 46a driven by the motor 38a in turn drives a sprocket |24 through chain 41a. The sprocket |24 is mounted upon a splined shaft |25 which is journaled in the stationary bearing supports |26. A gear carrier |21, which carries a gear |26, is pivotally mounted on the shaft |25 `so that thevgear |28, which meshes continually with the teeth of shaft 25, may be brought into mesh with any one of the gears |29 which are mounted upon the shaft 50a of the differential device 52a. It will be seen that by moving the gear carrier |21 pivotally about the shaft |25 and by sliding the gear carrier along the shaft, the gear |20 may be made to mesh with any one of the gears |29. To this end, the gear carrier is provided with an extending handle |30 which extends through an 7',

aperture |3| in a plate I 32 carried by the bearing supports |26. As shown clearly in Figs. 15 and 16,

the opening |3| is of step-like formation to pro-V vide successive recesses or notches corresponding to the respective gears |20. The purpose of this is to enable locking of the gear carrier |21 in any one of the successive positions to maintain the movable gear |28 in mesh with a desired one of the gears |29.

' By means of this adjustable transmission device, the shaft 50a may be driven at different speeds to thus drive the shaft 64a through the differential device 52a. -From the. previous description, it will be apparent that the followback mechanism is thus operated at different speeds. Just as the adjustable lost-motion or time lag device of the first-described controlled unit may be varied to vary the eective rudder action, for example during different weather conditions, so also may the transmission device of the modified controlled unit be adjusted to vary the rudder action. Except for the elimination of the time lag or lost-motion device and its .associated adjusting elements and the replacement thereof by the variable speed transmission device, the modified form of the controlled unit shown in Figs.` 15 to 17 is similar in structure and operation to the previously described unit.

In Figs. 18 to 20, there is illustrated a modified form of the controlling unit which eliminates any possibility of false operation of the system due to v'rolling or like motion of the craft. In the case of a vessel, for example,'it is desirable, of course, Y that the steering system be operated only when the Vessel moves angula'rly in azimuth with respect to the desired course. If rolling or other such motion of the vessel should cause the steering system to operate, it will obviously tend to drive the vessel on its course, which, of course,

is objectionable. It will( 'be seen from Figs; 2 and 3, as described above, that the support for the light-responsive devices may move pivotally on its pivotal mountings i5, whereas the light beam projected from the reflector 35d on the compass card remains fixed in position. In the trically in a particular manner. As shown clear-A ly in Fig. 18, in this instance, there are provided light-responsive devices 20a, 21a and 28a corre-- sponding'to those of the previously described apparatus and, in addition, there are provided similar light-responsive devices 2Gb, 2lb and 28hV mounted in exactly the same manner diametrically'opposite the rst set of devices. As shown in Fig. 19, in this instance, there is provided la reflector |33 which serves to direct two beams Ain opposite directions toward the two sets of 'eviates in the opposite direction, the devices 21a and 2lb. are brought into alignment with v light-responsive devices. Normally, the two beams Afall upon the central devices 28a and 28h. If the ship deviates from its course in one direction, the devices "26a and 26h are brought into alignment with the two beams, while if the ship the two light beams. y

As shown in Fig. 2o, the iight-responsive qevices 28a and 28h areconnected rin series,` the 'devices 26a and 2Gb are'connected in series, and

the devices 21a ancY 2lb are also connected in series.. The three series circuits are connected to control devices similar to those shown in Fig.

14, only the control relays being shown. The.

both of the series-connected devices of that ciro cuit must be activated by the light beams. \If the craft deviates in one direction, both of the devices 26a and 26h will be activated and their circuit will be energized. If the craftdeviates in the opposite direction, the two devices 21a and 2lb will be activated and their circuit will be en-A ergized. Suppose, however, that the craft rolls excessively 'and causes a horizontal shifting of the entire light `device assembly, causing evices 26a and 2lb for example to move into alignment with the light beams, obviously 'the activation of these devices will not cause energization ofeither of their circuits and, therefore, the steering systemwin not be operated. Likewise, if the devices 26b and 21a are movedv into alignment with the beams,` the steering system will not be operated. Thus, this device eliminates the possibility of false operation of `the steering system /due to rolling or other motion. of the craft so that y thefsteering system is operated only when the craft moves in azimuth with respect to its course.

It will be apparent from the above description that the invention provides a flexible system embodying remote control of a controlled unit from a controlling unit and' enabling the controlling unit to be disposed at a position on the craft where .it will be subjected to minimum effect of rolling of the craft or other extraneous influences.` The system thus provides for accurate control in accordance with the deviation of the craft from its course. Moreover, the system provides for adjustment vof the response'thereof and adjustment of the follow-back action, thus enabling it to be adapted to varying conditions, and it also provides for remote cntrol of the controlling unit by the controlled'unit to enable manual variation of the crafts course at will. It will be noted also that the system is simplified by the` provision of only twoicompact unitswhich makes it highly practical and well adapted forthe purposes in view. Y

It will be understood, of course, that the invention is not limited to the specific embodiments' herein disclosed but is capable of variou'smodiflcations, particularly in details thereof without departing from the spirit and scope ,of the invention. J l v I claim:

1. In an automatic steering system for a dirigible craft having a steering mechanism, a con- -trolling unit disposed on said craft at a tranquil position thereof and comprising means for providing a fixed light beam and a plurality of lightcsensitive devices movable with respect to said beam in response to deviation of the craft from its course, means for adjusting said devices relative to one another to vary the response of said controlling unit, a controlledv unit disposed lon said craft at a position remote rfrom said con'.-

trolling unit and comprising means controlled by said devices for actuating said steering mechanism in accordance with the crafts deviation, and means operable by said actuating means for effecting follow-back movement of said devices relative to said beam.

2. 'In an automatic steering system for a dirigible craft having a steering mechanism, a controlling unit disposed on said'craft at a tranquil 4 position thereof and comprising means responsive to deviation of the craft from its course, a

controlled unit disposed on said craft at a position remote from said controlling unit and comprising means controlled by said first means fon actuating said steering mechanism in accordance with the cra/fts deviation, means operable by said actuating means for effecting follow-back action of said first means, andmanually adjustable means on said controlled unit for introducing a variable time lag in the follow-back action.

3. In an automatic steering system for a'. dirigible craft having a steering mechanism, a controlling unit disposed on said craft at a tranquil position thereof and comprising means responsive to deviation of the craft from its course, a controlled unit disposed on said craft at the steering position thereof and comprising means controlled by said first means for actuating said steering mechanism in accordance with the crafts deviation, means on said controlled unit' operable by said 'actuating means for indicating the crafts course, means operable by said actuating means for effecting follow-back action of said first means, and means on said controlled unit operable at will for rendering said actuating means incapable of actuating said steering mechanism.

4. In an automatic steering system for a dirig-` ible craft having a steering mechanism, a controlling unit disposed on said craft at a tranquil 'position thereof and comprising means responsive to deviation of the craft from its course, a

controlled unit disposed on said craft at a position remote from said controlling unit and comprising means controlled by said first means for actuating said steering mechanism in accordance with the crafts deviation, means including a mechanical connection between said units operable by said actuating means for effecting follow-back action of' said first means, and manually adjustable means on said controlled unit for introducing a variable time lag in the operation of said mechanical connection.

v 5. In an automatic steering system for a dirigible craft having a steering mechanism, a controlling unit disposed -on said craft at a tranquil position thereof and comprising means -vresponsive to deviation of the craft from its course, a controlled unit disposed on said craft at a position remote from said controlling unit and comprising means controlled by said first means for actuating said steering mechanism in accordance with the crafts deviation', means including a flexible mechanical connection between said units operable by said actuating means for effecting follow-back action of said first means, manually adjustable means on said controlled unit for introducing a variable time lag in the operation of said mechanical connection, and manually operable means on said controlled unitfor actuating said mechanical connection to change lthe crafts course at will.

6. In an automatic steering'system for a dirigible craft having a steering mechanism', means responsive to deviation of the craft from its effecting a driving connection 4between said first` elementand one of said spaced elements when said first'ele'ment is actuated, and means operable by said shaft for effecting follow-back action of said first means. A y f 7. In an automatic steering system for a dirigible craft having a steering mechanism, means responsivev to `deviation of the craft from its course, means controlled by said first means for actuating said steering mechanism to bring the craft back on its course, a rotatable shaft having a threaded portion, a power transmission element threadedly mounted on saidshaft portion, power transmission means connecting said actuating means to said element, a pair of spaced elements on said shaft defining the range of axial movement of saidfirst element, cooperative clutch means on said elements for effecting a sion means connecting said actuating means to said element, a pair of spaced elements on said shaft defining the range of axial movement of said first element, one of said spaced elements being threadedly mounted on said shaft portion for axial movement therealong, manually operable means for adjustingAsaid one element axially of the shaft to provide a desired spacing of said pair of elements, cooperative clutch-means on said elements for effecting a. driving connection between said first element and one of said spaced elements when said first element is actuated, and

low-back action of said first means.

9. In an automatic steering system for a diri- 4 gible craft having a steering mechanism, means responsive to deviation of the craft from its. course, means controlled by said first means for 'actuating said steering mechanism to bring the.

craft back'on its course, a rotatable shaft having a threadedY portion, a power transmission element threadedly mounted on said shaft portion, power transmission means connecting said actuating means to saidkelement, a pair of spaced elements on said shaft defining the range of axial movement of said first element, one of said spaced elements being threadedly mounted ori.

said shaft portion for axial movement therealong, manually operable means including a differential gear device for adjusting said one element axially of the shaft to provide a desired spacing of said pair of elements, .cooperative clutch means on said elements for effecting a driving connection between said-first element and one of said spaced elements'when said first element is actuated, and means operable by said shaft for effecting follow-back action of said first means.

- means operable by said shaft for effecting fol-l l .evo

8 nanou l 10. In an'automatic steering system for a dirigible craft having a steering mechanism, means responsive to deviation of the craft from its course, means controlled by said first means for actuating said steering mechanism to bring the craft back on its course, a rotatable shaft -having a threaded portion, a power transmission element threadedly mounted on said shaft portion, power transmission means connecting said actuating means to said element, a pair f'spaced elements on said shaft ,defining th range of axial movement of said rst element, one of said spaced elements beingv threadedly mounted on said shaft portion for axial movement therealong, a dierential gear device forming a driving connection between said one element and said shaft while permitting axial adjustment of said element, manually adjustable means operable through said differential gear device for adjusting said one element axially of the shaft to provide a desired spacing of said pair of elements,

cooperative clutch means on said elements for' effecting a driving connection between said first vvelement and one of said spaced elements when said first element is actuated, and means operable by said shaft for effecting follow-b'ackaction of said first means.

1l. In an automatic steering system for a dirigible craft having a steeringmechanism, means responsive to deviation o'f the craft from its course, means controlled by said first means for actuating said steering mechanism to bring the craft back on its course, a rotatable shaft having a threaded portion, a power transmission element threadedly mounted on said shaft portion, power transmission means. connecting said actuating means to said element, a pair of spaced elements.

on said shaft defining the range of axial movement of said nrst element, one of said spaced .elements being threadedly mounted on said shaft portion for axial movement therealonga diierential gear device forming a driving connection gear device between said first, haftv and said secl ond shaft, means operable b said second shaft for eifecting follow-back action of said first means, means operable by said second shaft for indicating the crafts course, and manually operable means including said second dierentlal gear device for actuating said second shaft independently of said first shaft to change-the crafts course at will.

12. In an automatic steering system for a Vdirigible craft having a steeringmechanism, a controlling unit disposed on said craft at a tranquil position thereof andcomprising means responsive to deviation of the craft from its course, a controlled unit disposed on said craft at a position remote from said controlling unit and comprising means controlled by said first means for /actuat- -ing said steering mechanism in accordance with the crafts deviation, means operable by said actuating means for effecting'follow-back action of said first means, and manually adjustable means on said controlled unit for varyingthe rate of the follow-back action to vary the amount of actuation of said steering mechanism fora given deviation of thecraft from its course.

13. In an automatic steering system for a dirigible craft having a steering mechanism, a con- 5 trolling unit disposed on said craft at a tranquil position thereof and comprising means responsive to deviation of the craft from its course, a

controlled unit disposed on said graft at a position remote from said controlling unit and com- 10 prising means controlled by said rst means for actuating said steering mechanism in accordance with the crafts deviation, means operable by said actuating means for effecting follow-back action of said first means, and a manually adjustable 15 transmission device on said controlled unit for varying the rate of theA follow-back action to vary lsaid beams, a pair of spaced vserially-connected 25 beam-responsive devices normally out of line with said beams and adapted to be brought into line with the beams when the craftdeviates in one direction from its course a predetermined amount a second pair of spaced serially-connected beam- 30 responsive devices normally out of line with said beams and adapted to be brought into line with the beams when the craft deviates in the opposite direction from its course a predetermined amount, means controlled by said devices for actuating $5 said steering mechanism, means controlled by said first-mentioned beam-responsive means for maintaining said actuating means inoperative as long as said craft remains on its course, and

follow-back means operable by said actuating 40' means for returning said devices to normal position.

15. In an automatic steering system for a dirigible craft having a steering mechanism, means for providing a pair of beams of radiant energy, 45 a pair of spaced serially-connected beam- Y responsive .devices normally in line with said beams and adapted to be moved out of line with the beams when the craft deviates from its cour. a second pair of spaced serially-connected beam- 50 responsive devices normally out of line with said beams and adapted to be brought into line with the beams when the craft deviates in one direction from its course a -predetermined'amountb a third pair of spaced serially-connected beam- 55 low-back means operable by said actuating means d5 for returning said devices t9,.normal position.

, 16. In an automatic steering system for a dirigible craft havinga steering mechanism, a source `of two xed beams of radiant energy directedl horizontally'in diametrically opposite directions 70 from acentral point, al horizontal supportV arranged for rotation in either direction -about said point in response to deviations of the craft in azimuth from its course in either direction, aj, pair of spaced serially-connected beam-responsive '75 beams and the beams activate both devices of4 the pair, the said devices being non-responsive to any movement of the craft causing the beams to 'impinge on the devices in any other manner,

means controllable by either pair of serially-connected devices for actuating said steering mechanism, and followback means operable by said actuating means for restoring the normal relation between said beams and said devices.

17. Direction indicating apparatus for dirigible craft, comprising means at a relatively tran- ,qu.il position on said craft for detecting directional deviations of the craft, said means com prisng a light beamv and a plurality of lightresponsive devices arranged 'cooperatively with said beam, a direction indicator at another position on saidcraft, a motor arranged to actuate said indicator, means controlled by certain of said devices for energizing said motor whenever a directional deviation of the craft takes place exceeding in amount a predetermined minimum,

'follow-up means for restoring the normal relation of said devices to said beam, yand means controlled by another of said light-responsive devices, for maintaining said motor at standstill when the said normal relation obtains and when the directional deviation of the craft is less than .the said predetermined minimum.l

18. Direction indicating apparatus for dirigible craft, comprising means at a relatively tranquil position on said craft for detecting directional deviations of the craft, said means comprising a directionally fixed light beam and at least three light-responsive devices'arranged cooperatively with said beam, a direction indicator at another position on said craft, a'motor arranged to actuate said indicator, meansA controlled by one of said devices for energizing said motor in one direction in response toa deviation of the craft greater than a predetermined minimum in a given direction, means controlled by another of said devices for energizing said motor in the other direction in response to a deviation of the craft greater than the predetermined minimum in the other direction, follow-'up means for restoring the normal relation of said devices to said beam, and means controlled by a third light responsive device for maintaining said motor at standstill when said normal relation obtains and the directional deviation of the craft is less than the said predetermined minimum.

A 19.1nasteeringsystemfora-dirlgibleaft having a steering mechanism, means at a relatively tranquil position on said craft for detecting directional deviations of the craft, said means comprising a directionally fixed light beam and a light-sensitive cell assembly movable relative .to

said beam, a motor for actuating said steering mechanism, means controlled by the light-sen sitive cells for energizing said motor whenever-a -directional deviation of the craft takes place,

a follow-up 4connection to said cell assembly actuted by said motor, a direction indicator at another position on lsaid craft actuated by said motor, and manual means at said other position for actuating said connection and said Yindicator at will, to thereby move said cell assembly and change the direction of the craft accord- `ing to the reading of said indicator.

20. In a steering system for a dirigible craft having a ,steering mechanism, means at a relatively tranquil position on said 4craft for detecting directional deviations `of the craft, said means comprising a directionally fixed light beam and a light-sensitive cell assembly movable relative to said beam, a motor for actuating said steering mechanism, means controlled by the light-sensitive cells for energizing said motor whenever a directional deviation of the craft takes place, a driven member actuated by said motor, a direction indicator at a position remote from said first-mentioned position actuated by said driven member to thereby indicate the course of the craft, follow-up means between said driven member and said cell assembly, and manual `means at said remote position for actuating said driven member at will, to thereby move said cell assembly and change the direction of the craft according to the reading of said indicator.

21. In a steering system for a dirigible craft having a steering mechanism, means at a rela-A tively tranquil position on said craft for detecting directional deviations of the craft, said means comprising a directionally fixed light beam and a light-sensitive cell assembly movable relative to said beam, a motor for actuating said steering mechanism, means controlled by the light-sensitive cells for energizing said motor whenever a directional deviation of the craft takes place,

a dierential gear device connected to said motor,

low-up means between said driven member and saidceil assembly, and manual means at said remote position for actuating said driven membei' at will, to thereby move said cell assembly and change the direction of the craft accordin to the reading of said indicator.-

. BRITI'ON CHANCE. 

